I.LED energy-saving lamp is a new generation of lighting source after compact fluorescent lamp.
Leds, or semiconductor light-emitting diodes, are solid-state semiconductor devices that convert electricity directly into light. LED energy-saving lamp is a white LED light source with high brightness, high efficiency, low power consumption, long life, easy to control, maintenance free, safety and environmental protection; It is a new generation of solid cold light source, the light color is soft, gorgeous, rich and colorful, low loss, low energy consumption, green environmental protection, suitable for family, shopping mall, bank, hospital, hotel, hotel and other public places. No flash direct current, good protection for eyes, the best choice for lamp and flashlight.
LED, LED heart is a semiconductor chip, one end of the chip attached to a bracket, one end is a negative pole, the other end is connected to the positive pole of the power supply, the whole chip is encapsulated by epoxy resin. A semiconductor chip consists of two parts, one is a p-type semiconductor, in which the holes are dominant, the other is an n-type semiconductor, and the other is dominated by electrons. But when the two semiconductors are connected, they form a p-n junction. When a current passes through the wire on the chip, the electrons are pushed into the p-zone, where they recombine with the hole and emit energy as photons, which is how leds glow. Because LED lamps do not generate much heat, they convert electrical energy into light energy as much as possible. However, ordinary lamps generate a lot of heat and convert a lot of electrical energy into heat energy, which is wasted. LED lighting, by contrast, is energy efficient.
As a category of LED general lighting, LED energy-saving lamp derives its name from traditional lighting bulb lamp and energy-saving lamp. The appearance of LED energy-saving lamps is similar to that of traditional energy-saving lamps, which can meet the traditional aesthetics of consumers. LED energy-saving lamp features: low cost, high luminous efficiency, large luminous area, no glare, no ghosting.
1. High efficiency and energy saving: compared with the same brightness, 3W LED energy-saving lamp consumes 1 kilowatt hour in 333 hours, while ordinary 60W incandescent lamp consumes 1 kilowatt hour in 17 hours and ordinary 5W energy-saving lamp consumes 1 kilowatt hour in 200 hours.
2, long life: semiconductor chip light, no filament, no glass bubble, not afraid of vibration, not easy to break, service life can reach 50,000 hours (ordinary incandescent lamp service life is only 1,000 hours, ordinary energy-saving lamp service life is only 8,000 hours).
3, health: light healthy light contains less ultraviolet and infrared radiation (ordinary light line contains ultraviolet and infrared radiation).
4. Green environment protection: free of harmful elements such as mercury and xenon, which is conducive to recycling. Common lamp tubes contain mercury, lead and other elements.
5, vision protection: dc drive, no stroboscopic (ordinary lamps are ac driven, will inevitably produce stroboscopic).
6, high light efficiency: a company in the laboratory high photosynthetic efficiency has reached 260 lm/W, and the single star on market has reached 100 lm/W high power LED, LED bulbs, due to loss of power efficiency, the light of the lamp shade loss, actual photosynthetic efficiency in 60 lm/W, and incandescent lamp is only 15 lm/W, good quality energy-saving lamps at around 60 lm/W, so in general, the LED energy-saving lamps lighting and energy-saving lamps flat or slightly better. (data in May 2011)
7, high safety coefficient: the required voltage, current is small, small safety hazards, in the mine and other dangerous places.
8. Great market potential: low voltage, dc power supply, battery power supply, solar power supply, in remote mountainous areas and outdoor lighting and other places with low power supply.
iii.Choose LED energy-saving lamp
1. LED brightness (MCD) varies with price. Used for LED lamps and lanterns, the LED should comply with the laser level Ⅰ class standard.
2. Antistatic ability. Anti - static LED, long life, so the price is high. Leds with an anti-static rating of more than 700 volts are usually required for LED lighting
3. LED with the same wavelength and the same color. If the same color is required, the price will be high. Manufacturers without LED spectrometers struggle to produce products with pure colors.
4. Leakage current LED is a unidirectional conductive luminous body. If there is a reverse current, it is called leakage current.
5, luminous Angle different USES of LED its luminous Angle is not the same. special
Luminous Angle, higher price. If all diffuse Angle, the price is higher.
6. Different life spans. The key to quality is longevity, which is determined by light decay. Light decay small, long life; Long life and high price.
7. The luminescent body of chip LED is chip. The price varies greatly with different chips. The chip of Japan, the United States is more expensive, general Taiwan and domestic chip price is lower than Japan, the United States.
The chip size is expressed by the edge length. The quality of the large-chip LED is better than that of the small-chip LED. The price is proportional to the chip size.
9, colloidal ordinary LED colloids are generally epoxy resin, add anti uv and fire retardant LED price is more expensive, high quality outdoor LED lighting should be anti uv and fire prevention. Each kind of product will have different design, different design is suitable for different USES, LED lighting reliability design aspects include: electrical safety, fire safety, applicable environment safety, mechanical safety, health safety, safe use time and other factors. From the point of view of electrical safety, it should comply with relevant international and national standards.
Drive power supply
1. High reliability: especially the driving power of LED street lamp, which is installed in the high altitude, is not convenient to repair and costs a lot.
2. High efficiency LED is energy saving product, the efficiency of driving power supply is high. It is particularly important for the structure where the power supply is installed in the lamp. Because the luminous efficiency of LED decreases with the increase of LED temperature, the cooling of LED is very important. The efficiency of the power supply is high, its consumption power is small, the heat in the lamp is small, also reduced the temperature rise of the lamp. It is beneficial to delay LED light decay.
3. High power factor: the power factor is the load requirement of the power grid. General 70 watts of electrical appliances, no mandatory indicators. Although the power factor of individual electrical appliances with small power is a little lower on the impact of the grid, but at night we light, the same load is too concentrated, will produce serious pollution to the grid. For the 30-40 watt LED drive power supply, it is said that in the near future, there may be certain power factor requirements.
4. Driving mode: there are two kinds of current: one is a constant voltage source to supply multiple constant current sources, and each constant current source alone provides power to each LED. In this way, the combination is flexible, and the LED failure will not affect the work of other leds, but the cost will be slightly higher. The other is direct constant current power supply, LED series or parallel operation. Its advantage is low cost, but poor flexibility, but also to solve one LED fault, does not affect the operation of other LED problems. These two forms coexist for a period of time. Multi-channel constant current output power supply mode, in terms of cost and performance will be better. Maybe it's going to be the mainstream.
5. Surge protection: LED anti-surge ability is relatively poor, especially anti-reverse voltage ability. Strengthening protection in this area is also important. Some LED lights are installed outdoors, such as LED street lamps. Due to the swing of power grid load and the induction of lightning strike, various surges will be invaded from the power grid system, and some surges will lead to the damage of LED. Therefore, LED drive power should have the ability to suppress the invasion of surge and protect LED from being damaged.
6. Protection function: in addition to conventional protection function, it is better to add negative feedback of LED temperature in constant current output to prevent LED temperature from being too high.
7. Protection: lamp outside the installation type, power structure to waterproof, moistureproof, shell to be light resistant.
8. Led power supply is an important factor affecting led lamps. The life of the drive power should be matched with the life of led. This has a great impact on led lights. If there is a problem with the power supply, the consequences will be devastating. If anyone can have a breakthrough in the power supply in the future, it will be a major contributor to the led field.
9. To meet the requirements of safety and electromagnetic compatibility.
The LED heat dissipation
1. Aluminum fin for heat dissipation
This is the most common way to dissipate heat, using aluminum fins as part of the shell to increase the heat dissipation area.
2. Heat-conducting plastic shell
The plastic shell is filled with thermal conductive materials during injection molding to increase the heat conduction and heat dissipation capacity of the plastic shell.
3. Surface radiation heat dissipation treatment
The lamp shell surface does the radiation heat dissipation treatment, is simply smearing the radiation heat dissipation paint, may take the heat from the lamp shell surface with the radiation way.
Using the shape of the lamp shell, the convective air is produced, which is the lowest cost way to strengthen the heat dissipation.
5. The fan
Inside the lamp shell, long-lived and efficient fan is used to strengthen heat dissipation, with low cost and good effect. But it's a little trickier to change the fan, and it's not suitable for outdoor use, which is rare.
6. Heat pipe
Heat transfer tube technology is used to transfer heat from LED chip to shell fin. In large lamps such as street lamps are common designs.
7. Liquid bulb
The transparent liquid with high thermal conductivity is filled into the bulb by liquid bulb encapsulation technology. This is in addition to the principle of reflection, the only use of LED chip light surface heat conduction, heat dissipation technology.
8. Use of lamp holder
In the household LED lamps with low power, the internal space of the lamp holder is often used to place part or all of the driving circuit that generates heat. This can be used as a screw lamp holder with a large metal surface, because the lamp holder is tightly connected to the metal electrode and power cord. So some of the heat can be derived from this heat dissipation.
Integration of heat conduction and heat dissipation -- application of high thermal conductivity ceramics
The purpose of heat dissipation of lamp shell is to reduce the working temperature of LED chip. Due to the large gap between the expansion coefficient of LED chip and the expansion coefficient of metal heat conduction and heat dissipation materials commonly used by us, the LED chip cannot be welded directly, so as to avoid the damage of LED chip by high and low temperature thermal stress. The latest high thermal conductivity ceramic material, thermal conductivity is close to aluminum, expansion system can be adjusted to sync with the LED chip. In this way, heat conduction and heat dissipation can be integrated, reducing the intermediate link of heat conduction.
The performance of led lamps is affected by many aspects, only by fully considering all aspects can we produce qualified products. As an led production enterprise, only by giving full play to innovative thinking and developing its own core technology can it gain a foothold in the market. Led lamps are mainly produced in shenzhen and zhongshan, occupying most of the market share in China, while the development in the north is relatively backward due to the influence of the industrial chain.
As a new generation of energy-saving light source, led energy-saving lamp has a broad application prospect, but there are still many technical problems in front of it. We look forward to the improvement of the market